feat: M0 monorepo skeleton with services, clients, deploy and CI

- api/openapi.yaml: contract with /healthz, /readyz, /api/v1/server-info
- services/api (Go): api with oapi-codegen strict server, goose migrations,
  readiness checks for Postgres/Redis; storage-agent stub with internal token
- services/recommender (Python, uv): FastAPI health/readiness/internal status,
  `pipu-rec serve` and `pipu-rec analyze` entrypoints
- packages: generated api-client, core (server URL + server check),
  i18n (ru/en + dictionary check), design-tokens (CSS vars + TS from tokens.json)
- apps/web: Vite + React shell showing server status, language switch
- apps/mobile: Expo (SDK 53) Android app with server connect screen
- deploy: Dockerfiles, compose (prod + dev), nginx template, install/update scripts
- .gitea/workflows: ci.yml and tag-based release.yml (images, signed APK, release)
- scripts/version.mjs: version and Android versionCode from git tag
- tests/fixtures/music/generate.sh: synthetic test library via ffmpeg
- docs: versionCode formula, OpenAPI 3.0.3, dev instructions in README

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

services/api/cmd/api/main.go

@@ -0,0 +1,99 @@
+// Команда api — публичный REST API Pipu Music.
+package main
+
+import (
+	"context"
+	"errors"
+	"log/slog"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+
+	"pipu/api/internal/buildinfo"
+	"pipu/api/internal/platform/config"
+	"pipu/api/internal/platform/db"
+	"pipu/api/internal/platform/httpx"
+	"pipu/api/internal/server"
+	"pipu/api/internal/system"
+)
+
+func main() {
+	if err := run(); err != nil {
+		slog.Error("api stopped", "err", err)
+		os.Exit(1)
+	}
+}
+
+func run() error {
+	cfg, err := config.Load[config.API]()
+	if err != nil {
+		return err
+	}
+	log := httpx.NewLogger(cfg.LogLevel)
+	slog.SetDefault(log)
+
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	pool, err := db.Connect(ctx, cfg.DatabaseURL)
+	if err != nil {
+		return err
+	}
+	defer pool.Close()
+
+	if cfg.MigrateOnStart {
+		if err := db.Migrate(ctx, pool); err != nil {
+			return err
+		}
+		log.Info("migrations applied")
+	}
+
+	redisOpts, err := redis.ParseURL(cfg.RedisURL)
+	if err != nil {
+		return err
+	}
+	rdb := redis.NewClient(redisOpts)
+	defer func() { _ = rdb.Close() }()
+
+	sys := system.NewHandler(system.Info{
+		Version:               buildinfo.Version,
+		SupportedLocales:      cfg.SupportedLocales,
+		MinAndroidVersionCode: cfg.MinAndroidVersionCode,
+	}, map[string]system.Checker{
+		"postgres": system.CheckerFunc(pool.Ping),
+		"redis":    system.CheckerFunc(func(ctx context.Context) error { return rdb.Ping(ctx).Err() }),
+	})
+
+	srv := &http.Server{
+		Addr:              cfg.HTTPAddr,
+		Handler:           server.NewRouter(server.Deps{Log: log, System: sys}),
+		ReadHeaderTimeout: 10 * time.Second,
+	}
+	return serve(ctx, log, srv, cfg.ShutdownTimeout)
+}
+
+func serve(ctx context.Context, log *slog.Logger, srv *http.Server, shutdownTimeout time.Duration) error {
+	errCh := make(chan error, 1)
+	go func() {
+		log.Info("listening", "addr", srv.Addr, "version", buildinfo.Version)
+		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+			errCh <- err
+		}
+		close(errCh)
+	}()
+
+	select {
+	case err := <-errCh:
+		return err
+	case <-ctx.Done():
+	}
+
+	log.Info("shutting down")
+	shutdownCtx, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
+	defer cancel()
+	return srv.Shutdown(shutdownCtx)
+}